• Kaszuwara, Waldemar
• Lis, M.
• Michalski, Bartosz
• Leonowicz, Marcin

Abstract

In this study the SPS method was applied for low RE content (8,5% at.) and high RE content(13,5 % at.) MQ powders. The powders were sintered in a wide range of temperature, for 5 min., underpressure of 35 MPa. The low RE content grade, densified reluctantly and gained the density close to thetheoretical value only for 850 oC. The coercivity decreased gradually with increasing sinteringtemperature. On the other hand, the densification of the higher RE content grade powder occurred mucheasier and the coercivity, close to the theoretical value, was achieved already at 650 oC. The coercivity ofthis material also decreased with increasing sintering temperature. Microstructural studies revealed thatthe SPS sintering process leads to partial decomposition of the Nd2Fe14B phase. The proportion of theRE-rich and iron phases increases parallel to the increasing sintering temperature. On the basis of thecurrent results one can conclude that fabrication of high density MQ powders based magnets by the SPSmethod is possible, however the powders having higher RE content should be used for this purpose andthe sintering temperature as low as possible, related to density, should be kept.

Topics

• density
• impedance spectroscopy
• microstructure
• phase
• iron
• decomposition
• sintering
• densification
• coercivity